The problem can be corrected by upgrading the affected package to
version 3.00-8ubuntu1.5 (for Ubuntu 4.10), or 3.00-11ubuntu3.1
(xpdf-reader and xpdf-utils for Ubuntu 5.04) and 4:3.4.0-0ubuntu3.1
(kpdf for Ubuntu 5.04). In general, a standard system upgrade is
sufficient to effect the necessary changes.

Details follow:

xpdf and kpdf did not sufficiently verify the validity of the "loca"
table in PDF files, a table that contains glyph description
information for embedded TrueType fonts. After detecting the broken
table, xpdf attempted to reconstruct the information in it, which
caused the generation of a huge temporary file that quickly filled up
available disk space and rendered the application unresponsive.

The CUPS printing system in Ubuntu 5.04 uses the xpdf-utils package to
convert PDF files to PostScript. By attempting to print such a crafted
PDF file, a remote attacker could cause a Denial of Service in a print
server. The CUPS system in Ubuntu 4.10 is not vulnerable against this
attack.